Relay with clamp-contact assembly



July 21, 1959 D. ABRUucARl-.n 2,896,045

RELAY WITH CLAMP-CONTACT ASSEMBLY Filed Nov. e, 1957 United StatesPatent O RELAY WITH CLAMP-CONTACT ASSEMBLY Daniel Brunicardi, Wood Dale,Ill., assigner to Raymond T. Moloney, Chicago, lll.;A American NationalBank and Trust Company of Chicago, executor of said Raymond T. Moloney,deceased Application November 8, 1957, Serial No. 695,326

1 Claim. (Cl. 200-87) This invention relates to electromagnetic relaysand particularly to the provision of means for mounting movable contactson the armature for expeditious and economical manufacture.

In its more detailed aspects, the novel contact mounting means orassembly comprises a stack of insulating wafers between which thecontacts are gripped, together with a spring clamp of certain shapeadapted to straddle the stack and clamp the same against the top face ofan armature plate, with certain interlocking formations on the clamp andarmature coacting to effect a secure assembly capable of withstanding aconsiderable amount of abuse.

It is a further object to provide an armature-borne contact assemblymeans of simple and economical character making possible quickdetachment of the movable contact members for replacement orrearrangement.

Additional objects and aspects of utility and novelty relate to detailsof the construction and operation of the device described hereinafter inview of the annexed drawings in which:

Fig. l is a perspective view of a relay embodying the new armature-bornecontact assembly;

Fig. 2 is an exploded perspective of the armature contact assembly;

Fig. 3 is a vertical section through the nelay of Fig. 1 with partsshown in elevation;

Fig. 4 is a cross section through the contact assembly looking alonglines 4-4 of Fig. 3.

Fig. l shows a form of relay to which the contact assembly is suitablyadapted, the same consisting of a frame stamping having a forward lug 11to which is riveted at 12 an insulating panel 13 having atixed theretocertain stationary contacts 14.

On the opposite side of the frame (see also Fig. 3) is an upstandingwall 15 slotted on its top edge to seat a rockable armature plate 16.

Armature 16 is slotted as at 17 to receive the hooked nose 18A of aspring retaining clip 18 riveted as at 19 on said wall; and a tractionspring 20 is hooked at one end around the rim of said slot, and at theopposite end, onto a lug 18B of the spring clip, whereby the armature israised to its normal position of rest above the core plug 22 (Fig. 3) ofthe electromagnetic coil or bobbin 23 seated on the bight of the framepiece.

Referring mainly to Fig. 3, the clip-mounted, armature-borne contactassembly consists of a desired number of elongated spring-contact blades30 of the shape shown in Fig. 2, pierced with mounting holes 31 at a xedend, and tted with suitable contact points 32 at their free ends.

The pierced ends of the contact blades are disposed between pairs ofinsulating wafers 34 having bosses 35 on one face and matching recesses36 on their opposite faces, all adapted to register with the punches 31,such that when the blades 30 and wafers 34 are assembled in 2,896,045Patented July 21, 1959 ICC a stack, as in Figs. l and 3, the bosses 35tit into blade holes 31 and into the complementary recesses 36 so thatthe blades and stack of wafers form an interlocked set.

As seen in Fig. 2, the armature 16 is also provided with sets ofboss-receiving recesses 16X, by means of which the contact stack orassembly is registered in position on the top face of the armatureitself.

Means for securing the contact stack or assembly on the top of thearmature comprises a U-shaped clamp strap 40 of spring metal, such asPhosphor bronze, having a depressed face 41 constituting a pressure facelocated in the middle of the bight of the strap. The free end of eachside arm of the strap is turned back to provide a hook 42, the ends ofthese hooks respectively iitting into an undercut or depression 16X(Fig. 4) on the underside of the armature plate.

It will be apparent that the entire switch stack can be assembled with,or removed from, the armature at any time in the manufacture of therelay or subsequently, and that manufacturing costs in general can bereduced for relays of the class described by having the movable contactassembly seated and removably interlocked on the top face of thearmature in counter balance with the loading spring and the retaininglatch spring means 18 of the armature.

In the stack it is preferable that the uppermost plate 34X be of metalto afford a firm pressure surface.

The stack type switch assembly comprising at spring blades xed at oneend in a stack of thin, insulating wafers is a well-known construction,and some types of relay (eg. telephone relays) have been known to employclamps to secure stationary contacts in operative position on a frame.

The present disclosures provide a simple relay of the type in lwhichsome of the contacts are carried on the top face of a plate typearmature in a relation of counterbalance to a normal spring by a simplemeans which, except for the addition of the interlocking formations,requires little departure from conventional switch stack constructionsand methods; and no critical change in armature construction beyondproviding interlock means for the contacts on one face of the plate, andfor the removable clamp strap on the opposite face of the armatureplate, all without interference with the otherwise normal dispositionand operation of the armature.

In this manner there has been provided a cheap relay suited toexpeditious production and having a feature of easily removable orchangeable contacts which, save for the simple exceptions noted above,do not depart objectionably from conventional stack switch practices.

I claim:

In a relay of the type having a at armature plate mounted on a fulcrumnear one end thereof to rock in a sense normal to the magnetic axisthrough a pole of an electromagnet disposed at one side of said plate; aremovable contact assembly borne by said armatune and comprising atleast one elongated contact member carried at one end between at leasttwo insulating plates which are seated on said armature plate at thatparticular side of said fulcrum which is toward said magnetic axis sothat the weight of said contact assembly acts in a direction to rocksaid armature toward said electromagnet pole; spring means acting onsaid armature plate at an opposite side of said fulcrum from saidparticular side to rock the armature to a normal position oppositelyfrom the effort of the weight of said contact assembly; and means forremovably securing said contact assembly on the armature and comprisinga U-shaped flat spring strap straddling said insulating plates with therespective ends of the opposite side arms of said strap turned back toform wide hooks and passing around the side margins of said armatureplate and locking respectively by spring action in elongated slotsformed on the underside of said armature plate respectively adjacentsaid margins thereof, said slots having a length and Width substan- 5tially the same as the Width and thickness of the ends of said hooks tointert closely With the latter and prevent shifting movement of thestrap relative to the armature, together with cooperating boss andprotuberance means on the arrnature and insulating plates to further 10prevent shifting of the latter.

References Cited in the le of this patent UNITED STATES PATENTSLivingston Mar. 24, 1942 Obszarny June 3, 1947 Wilson May 24, 1949Jorgensen Oct. 16, 1951 Harrison Aug. 26, 1952 Bogue et al Feb. 21, 1956Peek July 23, 1957 Sauer Mar. 4, 1958

